Nutritional composition and sensory evaluation of cocoyam-based recipes enriched with cowpea flour

ABSTRACT

The study is on “Nutritional composition and sensory evaluation of cocoyam-based recipes enriched with cowpea flour”. The objective of this study is to evaluate the nutrients and chemical composition along with sensory qualities of cocoyam –based recipes enriched with cowpea flour, Data were analyzed using analysis of variance ANOVA and Duncan multiple range test to test significant differences between means p<0.05. Data analysis was done using Statistical Package for Social Science SPSS version 16.0 of SPSS. The moisture content is significantly different in Ebiripo than other blends. The physical and mechanical properties of cocoyam including shape, size, geometric mean diameter, viscosity bulk density gelatinization sphericity, color, mass, volume, particle density, surface area and compressive strength and the relationship of between size , surface area and weight have been identified to contribute to water retention. The increase in cowpea flour significantly increases the protein for all samples ojojo, ikokore, and ebiripo. The increase may be attributed to cowpea flour since cocoyam is known to have low protein. Based on the results of the study, the following recommendations are made: Enrichment of cocoyam-based foods should be encouraged. Nutritionists should create awareness and educate health workers and the general populace on the nutritive value of cocoyam recipes. The bioavailability of the nutrients should be carried out.  Substitution upto 50% cocoyam and 50% cowpea is recommended for vulnerable groups.

1.0     INTRODUCTION

1.1   Background of the Study

Cocoyam is an aroid herbaceous plant grown in damp shaded place. The family of cocoyam is the Aracea, made up of large family of monocots of about 1,500 species with a notable percentages distribution over the tropics (Ngoka 1997) of all these  species of cocoyam  belonging to this family only five or six produce edible products, the tree most important species of this Aracea family in Nigeria are colocasia esculents (Edeindia) xanthosoma roseum (Edeuhie) and colocasia spp (Anambe).

Taro belongs to the Genus colocasia which has numerious varieties and about 1,000 cultivars are recognized which fall mainly into two groups the eddoe which has a relatively small corm surrounded by large well developed cormels (and 42 chromosomes). And the dasheen which has a large central corm and numerous, but small cormels arising from its surface and 28 chromosomes (Onwu Eme,1987 & Kay.1987).

The two type of colocasia esculenta are frequently referred to as separate species in the literature, colocasia antiquorum and colocasia esculenta (kay 1987) but it is more generally accepted that the taros are a polymorphic species colocasia esculenta and under this classification the eddoe is colocasia esculenta, var. antiquorum  (syn colocasia esculenta var. globulifera) and the dasheen is colocasia esculenta var esculenta.

The taro variety is a perennial plant that grows 0.5-2m tall with an under ground starch corn which produces at it’s apex a whorl of large leaves which are thick with long robust petioles. The corms vary greatly in size and are cylindrical, up to 35cm long and 15cm in diameter, and are surrounded by a number of secondary corms (cormels). They are marketed by number ring a representing the mode of the stem while the root system is superficial and fibrous. Taro is grown on a wide range of soil types, but the best results are obtained on deep well-drained friable loans. In general the eddoes are harder than the dasheen and can be grown in dried conditions on poor soil.

1.1.1    Anti- Nutrients of cocoyam.

Phytic acid is an anti- nutrient that interferes with the absorption of mineral from the diet. Anti nutrient are natural or synthetic compounds that interfere with the absorption of nutrient (oxford dictionary.2006) Nutrition studies focus on those anti-nutrient commonly found in food source & beverages. One common example is physic acid which forms insoluble complexes with calcium, zinc, iron and copper (Chagen and Rackis ,1980) some proteins can also be anti-nutrient such as the trypain inhibitors and lection found in legumes (Guanietal 2005). These enzymes inhibitor interferes  with digestion. Another particular widespread in form of anti-nutrient is the flavonoids  which are a group phyphenolic compounds that include tannins (Beecher 2003). These compounds chelate metals such as iron and zinc and reduce the absorption of the nutrients, but they also inhibit digestive enzymes and may also precipitate proteins. Anti-nutrients are formed at a variety of reason. How ever their levels are reduced in modern crops, probably as an out come of the process of domestication (Phillips 1993). Nevertheless the large the fraction of modern diets that comes from a few crops particularly cereals, has raised concerns about the effects of the Anti- nutrients entirely using genetic engineering. But since these compounds may also have beneficial effects, such genetic modifications could make the foods more nutritious but not improve people’s health (Welch and Graham 2004).may traditional methods of food preparation such as fermentation, cooking and malting increase the nutritive quality of plant food through  reducing certain anti- nutrients such as phytic acid (Ho+2 and Gibson, 2007). Such processing methods are widely used in societies where cereals and legumes form a major part of the diet (Chavan, and Kadara 1989). An important example of such processing is the fermentation of cassava to produce cassava flour. This fermentation reduces the levels of both toxin and anti-nutrient in the tuber (Obah Andola Dumony, 2007).

1.1.2     Uses of Cocoyam

• It is often grown as ornamental plant
• It is also consumed as food in many parts of Africa.
• The corm taro can be used in variety of preparations in Hawaii, boiled corm is grounded into sticky paste known as poi.
• The corms are also employed in the preparation of burger, bread, flakes, muffin, chips, flour, cookie, ice cream etc.
• Cocoyam can be used to prepare oha soup of bitter leaf soup.
• Roasting: in olden days our grandparents used to roast the taro on hot coals or on a wood fire, they will then eat the roasted taro with roasted salt fish.
• The pericarp of the corm may be peeled before cooking or cooled and peeled later to eat withn any vegetable.
• Ekwang: A delicacy obtained by wrapping grated peeled corm with younger cocoyam leaves plus some palm oil, fish, shrimps, salt, magi and pepper.
• Koki beans: Prepared by mixing ground black eyed beans, palm oil, young cocoyam leaves, some salt and pepper and wrapping in plantain leaves.
• Achu: Prepared by pounding cocoyam mixed with banana and eating with yellow or black soup known as achu soup.
• Koki corn: Prepared by mixing ground fresh corn with palm oil, young cocoyam leaves plus some salt and pepper and wrapping in plantain leaves.
• Akwa: Prepared by pounding peeled boiled cocoyam and eating with egusi or any vegetable sauce.
• Kwacoco: Prepared by grating cocoyam, add some salt and wrapping in plantain leaves. It can also be called kwacoco bible, when palm oil, fish, shrimps, salt and pepper are added to the ground cocoyam and tied in plantain leaves and boiled.
• In Nigeria, it is used as thickener for soup and porridge.

1.1.3    Health Benefits of Cocoyam

• Cocoyams have more calories than potatoes. 100g provides 112 calories. Their calories mainly comes from complex carhohydrates known as amylase and amylopectin. However, the roots are very low in fats and protein than cereals and pulses. Their protein levels can be comparable to that of other tropical food sources like yam, cassava, potato, banana etc
• Cocoyam, however are free from gluten. They feature high quality phyto-nutrition profile comprising of dietary fibre and antioxidants in addition to moderate proportion of mineral and vitamin.
• It is one of the finest source dietary fibres; 100g flesh provide 4.1g or 11% of daily requirement of dietary fibre. Together with slow digesting complex carbohydrates, moderate amount of fibre in the food helps gradual rise in blood sugar levels.
• Cocoyam leaves as well as yellow-fleshed roots have significant levels of phenolic flavonoid pgment antioxidants such as β-carotenes and cryptoxathin along with vitamin A. 100g fresh cocoyam leaves provide 4825IU or 161% of RDA of vitamin A. Altogether; these compounds are required for maintaining healthy mucus membranes, skin and vision. Consumption of natural foods rich in flavonoids helps to protect from lung and oral cavity cancers.
• It also contains good levels of some of the valuable B-complex group of vitamins such as pyridoxine (vitamin B-6) folate, riboflavin, pantothenic acid and thiamine.
• Furthermore, the corms provide healthy amount of some important minerals like zinc, magnesium, copper, iron and manganese. In addition, the root has very good amount of potassium. The potassium is an important component of cell and body fluids that help regulate heart rate and blood pressure.
• Popular amongst diabetes in Africa, may be due to it content of loose carbohydrate in the form of starch rather sugar. Cocoyam has a low glycemic index. A low GI means that cocoyam affects blood sugar levels slowly without a sudden rise in the blood sugar level. Regular consumption of cocoyam is good for those who are trying to lose weight because of it low the caloric and high fibre content. Because cocoyam has minimal amount of fat, you can eat several servings of cocoyam and not worry about gaining unwanted pounds or other risks which are associated with fatty foods such as heart or kidney diseases.
• It is an ideal food for cancer prevention. Cocoyam has low fat and sodium contents, this makes it an ideal food for preventing hardening of the arteries which is usually cause by eating foods that are heavy in cholesterol.
• It also provides vitamin E which is a powerful antioxidants which helps to fight free radicals. This vitamin also aids in the metabolism of proper brain activities. Vitamin E is also essential for hair, skin and nails because of its antioxidants properties.
• Also provides copper which aids in growth and development of, eye function, hair health, how the body metabolizes iron, heart function and thyroid health.
• Provides vitamin C, maybe the most popular sought of vitamin as it is believed to boost the immune system. So vitamin C helps to prevent flu. We know it is essential in the diet as it is essential in the diet as it is one of the most powerful antioxidants because the body does not store this nutrients. Other than boosting the immune system, vitamin C also protect and reduces antioxidants because the body does not store nutrients. Other than boosting the immine system, vitamin C also protect and reduce skin aging, protect against prenatal problems related to health issues and diseases of the eye.

• Preparation

Taro corms and leaves should be processed and boiled before eating as they can be unpleasantly bitter and harmful for health when eaten raw. However, the plant parts are very safe after cooked, boiling, frying steaming etc.

 1.1.5      Introduction to Cowpea

Cowpea  (vigna unguiculate (L.)WALP) is cultivated around the word primarily as a pulse but also as a vegetable (for its leave as well as the green peas), as a cover crop and for fodder. It has many common named including black eyed pea, crowder pea, southern pea, inbia, niehe, coupe & frijole. It belongs to the family fabacea and its cultivated species V. unguiculate (syn v. sinences (L.) fruwith) includes 11sub  speciesand a large  number of related species, many of them grow as minor legumes or forage crops. Amongst these are V.subterrtanea (L.) verdc,V. radiats (L.) wilczek, V.angularia (wild) ohwi & H.ohashi and  V. umebellate (Thunb) ohwi and H. ohashi

Cowpea is an annual herbaceous plant with a large tap root and alternate trifoliate leaves and ovate leaflets. It shows considerable diversity in growth habit, flower and seed coat color. The standard flower vary in color from white, cream and yellow to purple and the seeds, which are smooth or wrinkled, range from white, cream or yellow to red, brown or black and are characterized by a marked hilum surrounded by a dark aril.

Cowpea is regenerated by seeds and is largely self pollinating but up to 2% out crossing has been reported (Ng and Hughes 1998, Fatokun & Ng 2007)

Cowpea (vigna unquiculata (L.) walp)is an important crop in many countries of tropical Africa, Asia and south America. Both grain and leaves are edible products of cowpea that are rich and cheap sources of high quality protein. They supplement to  the lower quality cereal or root and tuber protein commonly consumed in tropical Africa (Kich et al,1998: Karikari & Molatakgosi, 1999). an average cowpea grains contains 23-25% protein and 50-67% starch in dry bases (Quin 1997).

1.2      Objectives of the study

The objective of this study is to evaluate the nutrients and chemical composition along with sensory qualities of cocoyam –based recipes enriched with cowpea flour.

1.2.1    Specific Objective of this Study

The dietetic value of cocoyam – cowpea blend is enormous in many hospitals, especially in Nigeria so the dieticians in Africa will find the combination of cocoyam & cowpea highly nutritive in the treatment of malnutrition.

1.3       Significance of this Study

It is documented in the literature that blends of cocoyam and cowpea flour will improve the nutritive quality of the protein and the combination of cocoyam – cowpea flour could be used in the industrial production of baked foods, noodles and weaning foods. The result of this study will further provide information on the nutritional value of cocoyam.

The production  of this type of blend will increase the consumption of cocoyam and cowpea for better nutritional status of all age groups

1.4       Statement of problem.

To determine the nutritional composition and sensory qualities of cocoyam-based recipes enriched with cowpea flour.

And also to improve cocoyam based recipes ebiripo, ikokore, and ojojo using different blends of cocoyam (colocasia esculata) and cowpea (vigna unguiculata) flour.

Pages:  45

Category: Project     

Format:  Word & PDF        

Chapters: 1-5                                        

Material contains Table of Content, Abstract and References.